^^ I agree.
When I first got my horse he was pretty rank. He would rear and was pretty scary, to say the least.
I changed his feed (grass hay only), started him on some SmartCalm pellets, and began some serious ground training. It's been a year, and we went to our first big show about a month ago. He was an absolute dream! But it takes time, and you have to put the work in.
In a pinch, this stuff works pretty darn good. SmartCalm® Ultra Paste - Horse Calming Supplements from SmartPak Equine